Gree ME50-00 EG(M) commnad problem

1

Hello everyone,

I’m currently working on integrating a Gree Modbus gateway, model ME50-00 EG(M), with U-Match units.

So far, I’ve successfully read the main temperature variables by activating the XE70 thermostat and setting Function 10 to “remote monitoring” mode. With this configuration, I can read various registers without any issues. However, I’m encountering a problem:

  • I cannot send commands for:

    • Unit On/Off

    • Mode change

    • Fan speed adjustment

    • Setpoint modification

It seems that while the addresses are readable, they do not accept write commands and appear to be read-only.

These are the addresses I am attempting to control:

  • Unit On-Off

    • Address: 2

    • on_value: 0xAA

    • off_value: 0x55

  • Set mode

    • Address: 17

    • Expected values: 0x0001, 0x0002, 0x0003, 0x0004, 0x0101 (as per protocol)

  • Set fan speed

    • Address: 19

    • Expected values: 0, 1, 2, 3, 4, 5, 6

  • Set temp

    • Address: 20

My question is:

Is there any other parameter within the service functions (Function / Debug) that needs to be enabled to allow remote Modbus control (e.g., unit on/off, setpoint control)? Or is there an additional “remote control enable / BMS enable” setting that needs to be activated on the wired controller or the main board?

If anyone has used this specific ME50-00 EG(M) gateway or a similar setup with the XE70 and Function 10, and has successfully been able to write to these registers, I would greatly appreciate any guidance on what parameter I might be missing.

Thank you in advance.

5

Hello. Thank you for waiting.

Could you provide more details about the equipment you use to interface with the Gree Multi VRF System and what software you employ?

It appears you are not working with WirenBoard equipment.
I have not personally worked with the mentioned ME50-00 EG(M), but after reviewing the documentation (I have attached the link below… please also verify if this is the same documentation), I noticed a non-obvious detail: function codes for (0x0F) Write Multiple Coils and (0x10) Write Multiple Registers are used. Otherwise, it is standard Modbus control.
I did not come across any mention of write protection for the registers.

Modbus Protocol (V1.2) 2018.11.01.pdf (1.0 MB)